KCSAN: data-race in io_wqe_enqueue / io_wqe_worker

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 519d81956ee2 Linux 5.15-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11022e30b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=450d01a1c851e2a
dashboard link: https://syzkaller.appspot.com/bug?extid=a2c06908d6d1cad484f5
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [asml.s...@gmail.com ax...@kernel.dk io-u...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a2c069...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in io_wqe_enqueue / io_wqe_worker

write to 0xffff888105afbc04 of 4 bytes by task 5023 on cpu 0:
io_wqe_worker+0x7a/0x540 fs/io-wq.c:554
ret_from_fork+0x1f/0x30

read to 0xffff888105afbc04 of 4 bytes by task 5022 on cpu 1:
io_wqe_get_acct fs/io-wq.c:168 [inline]
io_wqe_activate_free_worker fs/io-wq.c:228 [inline]
io_wqe_enqueue+0x381/0x7f0 fs/io-wq.c:857
io_wq_enqueue+0x31/0x40 fs/io-wq.c:890
io_queue_async_work+0x13a/0x320 fs/io_uring.c:1473
__io_queue_sqe+0x422/0x460 fs/io_uring.c:6993
io_queue_sqe fs/io_uring.c:7011 [inline]
io_submit_sqe+0x88b/0x3eb0 fs/io_uring.c:7187
io_submit_sqes+0x505/0xde0 fs/io_uring.c:7293
__do_sys_io_uring_enter fs/io_uring.c:9986 [inline]
__se_sys_io_uring_enter+0x20d/0xb30 fs/io_uring.c:9928
__x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9928
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000c -> 0x0000000f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5022 Comm: syz-executor.3 Not tainted 5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.